The Cervical Spine

The neck is an upward extension of the spine beyond the body, designed to support and serve the needs of the head. It is amazingly designed and highly engineered so its underlying very complex function goes on in the background without us having to think about it. We can move and stop the motion of our heads very quickly, placing it very precisely within its very large range of motion, despite its weight and the leverage of its position. The head bears most of our very important sensory organs so the neck’s job is to put the head where it can perform its sensory function best.

The neck is a complex of bones, ligaments, joints, discs and muscles. However it is important not to forget the rich supply of nerves which flow down from the nearby brain and have a variety of functions. Nerve commands go to the muscles for movement, nerve impulses flow from the skin, discs, muscle and joints to inform the brain what is going on and help with balance, and other nerves control circulation to the area. The complexity and delicacy of the neck is in conflict with its need to provide maximum range of motion and this can lead to difficulties.

When the neck starts to give problems they are usually mechanical at least initially, in other words the symptoms vary with posture and what the person is doing physically with their neck. Neck symptoms typically include pain and loss of movement but can also cover a very long list of other symptoms such as headache, dizziness, vision disturbance, balance loss, weakness and mental difficulties. Restoration of a relative state of normality can be established by settling down the joint and other dysfunctions in the neck.

Large degrees of joint mobility are present in the cervical spinal region and this is partly made possible by the greater thickness of the intervertebral discs in the cervical region compared to the other spinal areas. Larger ranges of movement are possible with thicker discs, and the facet joints are structurally larger than similar joints in any other spinal areas. The large gliding motions which are possible in the neck allow its high levels of mobility in the compromise between mobility and stability in the spine.

The atlas and the axis vertebrae, known also as the C1 and C2 vertebrae, are structurally quite different from the other five neck bones and are designed to manage the movement and support of the skull. The atlas and axis joint, the atlanto-axial joint, has a structure which ensures it has very great rotatory ability and this joint contributes significantly to the rotation of the whole neck. Neck movements are very extensive and include extension, flexion, side flexions and rotations, facilitating our ability to precisely place our faces in a huge range of positions so that we can perform the activities we wish to.

Our thoracic spine is the basic foundation for the stability and mobility of the cervical spine. It facilitates the mobility of the neck and without this the neck would be subject to greater stresses where it meets the skull and the relatively stiffer thoracic spine. The neck sticks up narrowly to the skull with the muscles around it acting like wire ropes of a, holding it steady so it does not shake. Since the head is heavy and mostly in front of the centre of gravity this job is difficult and they must work hard to control balance of the head, which needs to be stable for our sense organs.

The neck flexor muscles, situated anterior to the neck, do not have a lot of work to do as they only really function strongly in getting up from lying down. It is a different story for the extensor muscles behind the neck as they have the job of keeping the head up for the whole day without tiring, only showing their function when we get tired in a train when sitting and our head flops forward as the extensors turn off. While balancing the forces applied to the neck and maintaining posture is their key function they also produce levels of compressive forces.